Chapter 2.2, Problem 1QQ

Interpretation Introduction

Interpretation:

The general formula for alkene having only one carbon‑carbon double bond has to be identified from the given options.

Concept Introduction:

Hydrocarbons are the organic compounds that contain only hydrogen and carbon atoms.  Hydrocarbon derivatives are the one in which the compounds contain hydrogen and carbon atoms along with one or more additional elements.  The additional elements that can be present in hydrocarbon derivatives are oxygen, nitrogen, sulphur, chlorine, bromine etc.

Hydrocarbons are further classified into two categories.  They are saturated hydrocarbons and unsaturated hydrocarbons.  The hydrocarbons that contain single bonds between carbon atoms in the entire molecule is known as saturated hydrocarbon.  The hydrocarbons that contain atleast one double or triple bond between two carbon atoms in the entire molecule is known as unsaturated hydrocarbon.

Saturated hydrocarbons are alkanes.  Unsaturated hydrocarbons are alkene, alkyne and aromatic hydrocarbons.

Alkane has general molecular formula as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  Alkene in which one double is present has general molecular formula as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  Alkyne in which one triple bond is present has the general molecular formula as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n-2}}$.  Cycloalkanes have the general molecular formula as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  Cycloalkenes in which one double bond is present have the general molecular formula as ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n-2}}$.